A machine that paints trafc stripes on roads is mounted on a truck and set to a width of 4 inches. Road crews adjust the mount to ensure the width is correct. A road inspector checks the width of 40 random stripes to see if the machine has slipped out adjustment. The mean diameter for this sample is x = 3.89 inches with a standard deviation ofs = 0.5 inches, Does this indicate that the machine has slipped out of adjustment and the average width of stripes is no longer ,4 = 4 inches? Use a 5% level significance. Conduct a t test to examine whether the mean width of stripes is different from 4 inches. (a) Calculate the test statistic. (Round your answer to two decimal places.) I = l1v7o x (b) Calculate the P-value. (Use a table or technology. Round your answer to four decimal places.) 0.9709 l x